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Health Information For Parents
A lumbar puncture, or spinal tap, is a medical test that involves collecting a small sample of cerebrospinal fluid (CSF) for examination. This clear, colorless liquid helps “cushion” the brain and spinal cord, or central nervous system.
Doctors use the fluid sample to look for signs of possible infections or other illnesses.
The central nervous system is made up of the brain and spinal cord. It’s the “command center” for the body. The spinal cord sends signals to and from the brain and the brain interprets them.
Cerebrospinal fluid constantly flows around the central nervous system while protecting it. Becausee it “bathes” the central nervous system, CSF can also pick up chemicals and impurities in the brain and spinal cord.
A fluid sample can provide a lot of important information about a person’s health. So a lumbar puncture can help doctors find or rule out many diseases or conditions.
Most often, a spinal tap is done is to see if a child has meningitis (inflammation and infection of the covering of the brain and spinal cord). Other conditions that can be detected include Guillain Barré syndrome, multiple sclerosis, cancer that affects the nervous system, and bleeding in the brain.
Spinal taps also can be used to add medicine, anesthesia, or dye (for specialized X-rays) directly into the cerebrospinal fluid. Occasionally, they’re done to help relieve pressure in the brain when a condition causes the body to make too much CSF.
If your child needs a lumbar puncture, you’ll have an opportunity to ask questions first. Then, you’ll be asked to sign an informed consent form, stating that you understand the procedure and its risks and give your permission for it.
Most spinal taps are done in the emergency department. The doctor doing it will know your child’s
but might ask a few questions, such as whether your child is allergic to any medicines.
Some parents choose to be in the room with their child during the spinal tap, while others are more comfortable in a waiting area. You can ask the doctor if it is OK for you to stay.
A spinal tap is a common procedure that takes about 30 minutes or less.
The spinal cord extends from the lower part of the brain down to the upper lumbar area. A spinal tap is done in the lower lumbar area, below the point where the spinal cord ends. So, the risk of harming the spinal cord is avoided.
A lumbar puncture is not a surgery. So someone getting one might be awake during it, and won’t need stitches or extended recovery time. If a child seems anxious or agitated, the doctor will recommend a sedative (a type of medicine that helps the patient relax during the procedure). The sedative can be given by mouth, nose, or through an IV.
Patients should be positioned with the back curved out so the spaces between the vertebrae are as wide as possible. This makes it easier for the doctor to insert the needle.
Older children may be asked to either sit on an exam table while leaning over with their head on a pillow or lie on their side. Infants and younger children are positioned on their sides with their knees under their chin. For these children, nurses or aides hold them securely in position.
When the patient is in position, a doctor will use sterilizing soap to clean the area where the needle will go in.
A small area on the lower back is numbed by a type of liquid anesthesia (medicine that helps prevent pain) given through a tiny needle. Often, a numbing cream is applied to the skin before this. The cream eases the discomfort of the injection, although the liquid medicine may burn a little.
The spinal needle is the most important tool of this procedure, and functions as the “tap.” The needle is thin and the length varies with the size of the patient. It has a hollow core. Inside the hollow core is a “stylet,” another type of thin needle that acts kind of like a plug. When the spinal needle is inserted into the lower lumbar area, the stylet is carefully removed, letting the CSF drip into the collection tubes.
Making sure the patient is in the proper position, a doctor carefully inserts the spinal needle between two vertebrae. The needle is carefully passed through skin and ligaments, and then through a tough membrane called the dura mater. Doctors can tell that the needle is in the right place when they feel a “pop,” which means the needle passed through the tough membrane. When the needle reaches an area called the spinal canal, the stylet is slowly pulled out to allow the cerebrospinal fluid to flow.
Occasionally, a small tool called a manometer is hooked up to the end of the needle. A manometer is basically a gauge that measures pressure of the CSF. High fluid pressure can be an indicator of some serious conditions, like tumors or hydrocephalus (excessive buildup of fluid in the brain).
Collecting the CSF sample usually takes about 5 minutes. Then, the needle is withdrawn and a small bandage is placed on the site. Collected samples are sent to a lab for testing.
If you were not in the room with your child during the test, you can come in after the samples have been collected. Depending on the doctor’s recommendations, your child might have to lie down on his or her back for an hour or so after the procedure.
Some results are available within 30 to 60 minutes. But to look for specific bacteria growing in the sample, a bacterial culture is sent to the lab. These results are usually available in 48 hours. If there might be an infection, the doctor will start antibiotic treatment while waiting for the culture results.
Lab technicians look for several things when examining the cerebrospinal fluid sample, including:
Lab technicians also do a Gram stain and culture on the sample. A Gram stain detects bacteria in a sample. This involves adding a kind of dye to it, then checking it for bacteria. Then the sample is cultured (put in special conditions to see if any germs grow from the CSF). This helps identify the specific type of infection.
A spinal tap is a safe procedure with few, if any, risks. Rarely, complications can include:
When your child is having any kind of procedure, it’s understandable to be a little uneasy. But it helps to know that spinal taps are brief, common procedures and complications are rare. If you have any questions or concerns, talk with your doctor.
A spinal tap is an important test for diagnosing illnesses, such as meningitis.
Find out how and why doctors perform lumbar punctures (spinal taps).
Encephalitis is an inflammation of the brain. Although encephalitis sounds scary, understanding its causes, symptoms, and treatment can help you feel prepared to deal with it if you ever need to.
Encephalitis is a rare brain inflammation caused by a virus. The best way to avoid encephalitis is to prevent the illnesses that may lead to it.
Meningitis is treatable, but can be serious. So it’s important to know the symptoms, and get medical care right away if you think that your child has the illness.
You may be wondering what the deal is with meningitis because you’ve heard frightening stuff about meningitis outbreaks in the news.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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